Leaving Cachi (km 0), after crossing the bridge on the Calchaquí, the route continues 10 km until Payogasta; 2 km later on, in the em-palme with the RP33, the asphalt ends. To continue toward the left, by the RN40, signalled. The road runs for a very open landscape, crossing streams that lower from the north, some quite wide and mighty ones in summer.
In km 19, without signalling, it leaves to the right an on the way to very uneven rubble, frequently crossed by the channel of the river and impossible to traffic in summer.
In 20 km it will take it to Herdsman of Payogasta.
Their declaration like National Historical Monument is in step. It is a pure Incan place that was part of an Inca road convincingly proven that, Tastil united with Payogasta. The most remarkable building is a kallanca, rectangular construction with roof to two waters and two or three internal divisions that it served as administrators' residence or military Incan and it is the only one that is in the Argentina . There is, also, an ushnu or platform ceremonial and enormous circular turrets of 5 m of diameter whose walls the 2 m of height still reaches. It is impactante and it is worth the effort of a deviation.
To return for the same road until the RN40 (km 19) and to advance for this toward the north. When arriving to the km 30, the road goes abruptly by the village of Old and low Town to the bottom of a deep gulch.
The walls of this last one, of red color, contrast highly with the green of the cultivations. Following 8 more km, they finish the cultivations and the houses, the landscape is enlarged again, and the road runs now very next to the river, with pastizales sprinkled by shady places, ideals for picnic.
In km 43 the hillsides narrow the step and 5 km later on the road it emerges of the bottom of the valley, returning the width of the views.
The route continues for a plain and far from the river. In km 50 cross Black Field, called this way because the floor appears covered "as if it had been sowed" by rounded and very porous stones of black color, evidencing its volcanic nature. As it seems they would have arisen, in remote times, of two chimneys opened up in the oriental mountain, well-known as The Twins.
In km 51 without signaling, it goes down to the left and perpendicular to the road a print that arrives until the pedestrian path that takes to the Devil's Throat, a place of remarkable beauty in 1.200 m , where the water of the river erosionó an onyx wall until crossing it, forming an underground channel of more than 50 m of long. It can lower until the level of the water and to penetrate inside the canyon.
In km 54 to the left, signalled, a road that crosses the river comes out and in 5 km it arrives to The Poma, the new town that rose then that the earthquake of 1930 destroyed the old one whose remains can visit one another to about 300 meters . The Poma is the last population with simple services, including a modest hostel, before beginning the ascent for the RN40 until the one opens up of Acay -4.895 meters - and, connecting with the RN51, to arrive to San Antonio de los Cobres in km 145.
Although the distance from The Poma to San Antonio de los Cobres is hardly something more than 90 km , this is a conserved difficult, risky, habitually bad road and impassable during the winter storms of snow.